<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>02_JS的变量与常量</title>

</head>
<body>
<script>
    var a = 1;
    console.log(a);
    var b = 3.14;
    console.log(b);
    var c = "hello world";
    console.log(c);
    var d = true;
    console.log(d);
    a = 5.5;
    console.log(a);
    var a = "哈哈哈"
    // console.log(a);
    const PI = 3.14;
    console.log(PI);
</script>
</body>
</html>